In general, various types of airbag modules such as an airbag for protecting a driver, and an airbag for protecting a passenger seated on a front passenger seat are mounted in a vehicle.
Among others, an airbag device for protecting a pedestrian is configured so that an inflator is mounted on a cowl top panel or a hood panel, and an airbag cushion is deployed toward a wind shield glass by an operation of the inflator, thereby protecting a head or an upper body of a pedestrian who collides with the vehicle, and thereafter, secondarily collides with the wind shield glass.
In this case, since the inflator is mounted on the cowl top panel or the hood panel, the inflator is horizontally installed in a left and right direction of a vehicle body. In addition, in most instances, a single inflator is installed at a central portion on the basis of the wind shield glass, and a discharge portion for discharging high pressure gas is formed at the inflator in only one direction.
Meanwhile, when the airbag cushion is deployed, the airbag cushion covers a lower end portion of the wind shield glass on the basis of the wind shield glass, and left and right upper portions of the airbag cushion are deployed to form an approximate “U” shape so as to cover left and right portions of the wind shield glass in order to protect the driver and the passenger seated on the front passenger seat.
However, since the inflator has the discharge portion for discharging high pressure gas which is formed in only one direction, as described above, there is a problem in that the high pressure gas eccentrically discharged to one side cannot be uniformly distributed to the left and right upper portions of the airbag cushion.
Korean Patent Application Laid-Open No. 10-2013-0048866 and Korean Utility Model Registration No. 20-0431748 disclose technical solutions for uniformly distributing high pressure gas discharged from a high pressure gas discharge portion of an inflator to ends of the airbag cushion.
In more detail, Korean Patent Application Laid-Open No. 10-2013-0048866 partitions an internal space into a plurality of divided chambers, and includes a diffuser pocket in which an inlet through which the high pressure gas is supplied from the inflator, and a plurality of gas discharge portions through which the high pressure gas is discharged to the divided chambers are integrally provided in a main cushion, in order to maintain internal pressure in the main cushion to be overall uniform.
Korean Utility Model Registration No. 20-0431748 relates to a side airbag module, the airbag module is provided in the vicinity of a gas discharge portion of the inflator, and formed in a pocket shape for dispersing the discharged gas, and includes a diffuser pocket having a diffuser discharge port that is opened upward, thereby achieving the uniform deployment of the airbag cushion.
However, since the divided chambers and the diffuser pocket in the related art need to be formed in the airbag cushion, there are problems in that a weight and costs of the airbag module are increased, it is difficult to uniformly distribute the high pressure gas into the airbag cushion because the high pressure gas is eccentrically disposed to one side from the gas discharge portion of the inflator, a reinforcing fabric is required to absorb high temperature heat and high pressure of the high pressure gas, and the supply of the high pressure gas to the upper portions of the airbag is impeded.